The present invention relates to a roll control system for countering the roll forces generated by a vehicle and, more particularly, to a hydraulically-operated roll control system that is activated by a threshold vehicle speed and steering angle.
Vehicle suspension systems are well known and typically comprise springs and dampers connecting the wheels to a vehicle body. These components support the mass of the vehicle and isolate the unevenness of the road surface from the vehicle passengers. When the vehicle turns, the suspension system permits the vehicle body to rotate slightly about its horizontal, longitudinal axis in response to the rolling force exerted on the vehicle body during the turn.
Further stabilization and control against the rolling force that occurs during turning has been achieved through the use of a stabilizer or anti-roll bar. For example, U.S. Pat. No. 5,161,822 discloses front and rear anti-roll bars which are connected to control arms on which the front and rear wheels are mounted. A hydraulically-operated roll control system is connected to the anti-roll bar to impart added roll correction while limiting the maximum displacement of the pistons in the roll control system, which in turn, limits the amount of correction afforded by the system.
Although the system described in U.S. Pat. No. 5,161,822 is useful, the art continues to seek improvements. One improvement is to provide a semi-active roll control system that counters the roll forces that are generated during turns but which can uncouple the anti-roll bar when cornering forces are not present.